Pressure indicator

ABSTRACT

Disclosed herein is a device which is intended to deliver and maintain reduced pressure to body surfaces for application of reduced pressure wound therapy (RPWT) also known as negative pressure wound therapy (NPWT). During application of this type of therapy, a substantially airtight seal is formed around a section of tissue to be treated. This seal is formed by a dressing which provides fluid communication from a section of tissue to a reduced pressure source. Disclosed herein is a dressing system which is configured to enhance usability and functionality of this dressing. First, the system may be configured to allow full rotation of the fluid communication conduit to the reduced pressure source along the axis substantially normal to the dressing. Second, the system may be configured to include a one-way valve to prevent backflow of any drainage fluids. Third, the system may be configured with transparent windows covered by opaque flaps to allow inspection through the dressing. Fourth, the system may be configured to include an indicator which visually makes clear whether reduced pressure is being applied or not. Fifth, the system is configured to minimize the profile of the dressing system.

CROSS-REFERENCE TO RELATED APPLICATIONS

This is a continuation of U.S. application Ser. No. 12/626,426, filed onNov. 25, 2009, which claims benefit under 35 U.S.C. §119(e) to U.S.Provisional Ser. No. 61/117,921, filed on Nov. 25, 2008, and to U.S.Provisional Ser. No. 61/117,920, filed on Nov. 25, 2008, which arehereby incorporated by reference in their entirety.

BACKGROUND

The use of sub-atmospheric pressure to treat wounds can be traced backto ancient civilizations. For example, the ancient Chinese used“Cupping,” a technique that creates reduced pressure environment byflaming then applying to the skin a glass chamber to draw out bad humorsfrom the body. Modern research has revealed that applying reducedpressure to damaged tissue may have several beneficial effects: 1) areduced pressure level may lead to retraction of the damaged tissueedges and thus may reduce the defect size and may expedite healing byfacilitating wound contraction; 2) the reduced pressure may providemechanical stimulation to the damaged tissue which may release growthfactors at the wound bed to promote healing; 3) the reduced pressure maycreate suction in the damaged tissue cavity which may remove necrotictissue from the damaged tissue cavity and may reduce bacterial load; 4)the application of reduced pressure may increase blood flow to thedamaged tissue which may expedite healing; 5) reduced pressure mayremove granulation inhibiting metalloproteinase enzymes which mayenhance tissue remodeling and healing.

SUMMARY OF THE INVENTION

Disclosed herein is a device which is intended to deliver and maintainreduced pressure to body surfaces for application of reduced pressurewound therapy (RPWT) also known as negative pressure wound therapy(NPWT). During application of this type of therapy, a substantiallyairtight seal is formed around a section of tissue to be treated. Thisseal is formed by a dressing which provides fluid communication from asection of tissue to a reduced pressure source. The dressing system maybe configured to enhance usability and functionality of this dressing,or to otherwise be configured with more optimal sealing characteristics,improved peri-wound skin protection, and with easier application thantraditional RPWT dressing systems. In some examples, the dressing maycomprise an adhesive layer comprising a flowable adhesive having asufficient volume or thickness to fill micro-cracks and fissures in theskin surface to reduce dressing leakage rates, as well as gaps in thedressing that may form when the dressing buckles or wrinkles. Theadhesive may also have moisture absorbent characteristics to reducetissue maceration.

The dressing system may be configured with any of a variety of otherfeatures. First, the system may be configured to allow full rotation ofthe fluid communication conduit to the reduced pressure source along theaxis substantially normal to the dressing. Second, the system may beconfigured to include a one-way valve to prevent backflow of anydrainage fluids. Third, the system may be configured with transparentwindows covered by opaque flaps to allow inspection through thedressing. Fourth, the system may be configured to include an indicatorwhich visually makes clear whether reduced pressure is being applied ornot. Fifth, the system is configured to minimize the profile of thedressing system.

In one embodiment, a reduced pressure treatment system is provided,comprising a cover structure comprising an outer edge, an upper surfacea lower surface, and at least one opening, a flowable adhesive layerattached to the lower surface of the cover structure, wherein theflowable adhesive layer has a thickness of at least about 0.2 mm, and anon-electrically powered, self-vacuum generating vacuum source. Thesystem may further comprise tubing configured to attach to the source.The vacuum source may be integrally formed with the cover structure. Thecover structure may further comprise a port member attached to at leastthe upper surface of the cover structure. The flowable adhesive layermay comprise a moisture absorbent flowable adhesive layer. In somevariations, the adhesive layer may have a water absorbency rate of atleast 900 g/m2/day, 1000 g/m2/day, 1100 g/m2/day or 1200 g/m2/day ormore. In some other examples, the flowable adhesive layer may have athickness of at least about 0.3 mm, about 0.5 mm, about 0.7 mm, about 1mm or at least about 1.5 mm. In some instances, the flowable adhesivelayer may have a viscosity in the range of about 20,000 to about 50,000centipoise, or about 10,000 to about 100,000 centipoise.

In another embodiment, a reduced pressure treatment system is provided,comprising a cover structure comprising an outer edge, an upper surfacea lower surface, and at least one opening, a port member attached to theupper surface of the cover structure and comprising at least one portlumen in communication with the at least one opening of the coverstructure, and a hydrocolloid layer attached to the lower surface of thecover structure, wherein the hydrocolloid layer has a thickness of atleast about 0.2 mm. The hydrocolloid layer may comprise a reducedthickness region about the outer edge of the cover structure. In someexamples, the reduced thickness region may comprise an embossed orcompressed region, and/or may comprise an increased density relative toan interior region of the hydrocolloid layer. In some examples, thesystem may further comprise visual grid markings on the cover structure.In further examples, the port member may further comprise a base and abody configured to rotate with respect to the base. The base of the portmember may be adhered to the upper surface of the cover structure. Thesystem may further comprise tubing, the tubing comprising an outer wall,a proximal end, a distal end, at least one lumen therebetween, alongitudinal lumen axis, a first dimension transverse to thelongitudinal lumen axis and a second dimension transverse to the firstdimension and the longitudinal lumen axis. The tubing may also beconfigured to attach to the port member, or may be integrally formedwith the port member. In some variations, the first dimension of thetubing may be greater in size than the second dimension, and in somevariations, may be at least twice the size of than the second dimension,three times the size or four times the size or more. The tubing may alsocomprise a plurality of lumens in a generally planar configuration. Insome examples, the at least one port lumen has a non-circularcross-sectional configuration, and may also comprise at least one lumenprojection, which may be a plurality of longitudinal ridges. The tubingmay also further comprise at least one side passageway providingcommunication between at least one lumen of the tubing and the outerwall. The system may also further comprise an elastomeric structuresealed to the outer surface of the tubing and covering the at least oneside passageway, wherein the elastomeric structure may be a sleevestructure. In other examples, the elastomeric structure may beconfigured with an interior surface that is spaced a first distance fromthe outer wall of the tubing when the interior surface is exposed toatmospheric pressure and a second distance less than the first distancewhen the interior surface is exposed to a reduced pressure. In stillother examples, the port member may comprise an elastomeric material.Sometimes, at least a portion of the elastomeric material may beconfigured to deform into the at least one port lumen when an internalpressure level within the at least one port lumen is at least about −50mm Hg, about −75 mm Hg, about −100 mm Hg, or −125 mm Hg lower thanatmospheric pressure. The cover structure may further comprise areinforcement structure, which may be integrally formed with the coverstructure. In some examples, the reinforcement structure comprises afirst ridge structure on the upper surface of the cover structure andsurrounding the port member. The system may also further comprise asecond ridge structure surrounding the first ridge structure. The firstridge structure may be a segmented ridge structure. In some examples,the reinforcement structure may be embedded within cover structure.

The cover structure may also comprise a cover material and thereinforcement structure comprises a reinforcement material with anincreased durometer than the cover material. The reinforcement structuremay comprise a grid reinforcement structure, or a radial spokestructure. In some variations, the system may further comprise a releaselayer releasably adhered to at least a portion of the hydrocolloidlayer. In some specific variations, the release layer may be releasablyadhered to a central portion of the hydrocolloid layer, and the systemmay further comprise at least one or two handle layer(s) releasablyadhered to at least a peripheral portion of the hydrocolloid layer andlocated between the hydrocolloid layer and the release layer. The systemmay also further comprise an adhesive carrier structure detachablyattached to the upper surface of the cover structure. The adhesivecarrier structure may comprise a first carrier layer and a secondcarrier layer and a non-linear interface therebetween. The adhesivecarrier may also comprise a central opening surrounding the port member.The central opening may be spaced apart from the port member, and insome variations, may be spaced at least 1 cm from the port member. Insome examples, the hydrocolloid layer may have a greater probe tackforce about the outer edge of the cover structure than about an interiorregion of the cover structure. The hydrocolloid layer may also have agreater release force about the outer edge of the cover structure thanabout an interior region of the cover structure. In some instances, themaximum perpendicular dimension of the port member to the coverstructure may be less than the maximum transverse dimension of the portmember that is transverse to the maximum perpendicular dimension, or maybe less than the maximum transverse dimension of the port member that istransverse to the maximum perpendicular dimension. The tubing may alsofurther comprise a one-way check valve.

In another embodiment, a method for performing reduced pressuretreatment of a skin location is provided, comprising applying a dressingto a skin location, applying a mask to the skin location, the maskcomprising an inner edge and an outer edge, applying a liquid sealant tothe dressing and the skin location, and removing the mask from the skinlocation. The method may also further comprise selecting the mask tospace the inner edge of the mask from the edge of the skin location. Itmay also further comprise placing a contact material onto the skinlocation, wherein the skin location is an open wound, placing a meshmaterial onto the liquid sealant after applying the liquid sealant tothe dressing, placing the mesh material onto the liquid sealant afterremoving the mask from the skin location, or placing a mesh materialonto the dressing before applying the liquid sealant.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 depicts an example of a dressing configured for use with a vacuumsource.

FIG. 2 is a schematic side elevational cut-away view of a connectorconfigured for use with a vacuum source.

FIG. 3A is a cross-sectional component view of the port assembly in FIG.2. FIG. 3B is a cross-sectional view of the port assembly of FIG. 3A inassembled configuration.

FIG. 4 illustrates another example of a dressing configured for use witha vacuum source.

FIG. 5 illustrates another example of a dressing configured for use witha vacuum source.

FIGS. 6A and 6B depict one example of a port assembly with a pressureindicator.

FIGS. 7A and 7B depict another example of a port assembly with apressure indicator.

FIGS. 8A and 8B depict another example of a port assembly with apressure indicator.

FIGS. 9A and 9B are superior and side elevational views of an example ofa low profile port assembly.

FIGS. 10A and 10B are superior elevational and side cross-sectionalviews of another example of a low profile port assembly; FIGS. 10C and10D are perspective cross-sectional views of various examples oflow-profile conduits of a low profile port assembly.

FIG. 11A is a perspective view of another example of a low profiledressing; FIG. 11B is a cross-sectional view of the low profile conduitof the dressing in FIG. 11A; FIG. 11C is cross-sectional view of analternate example of a low profile conduit.

FIG. 12 is another example of a port assembly with a pressure indicator.

FIG. 13 is a schematic illustration of another example of a low profileport assembly.

FIG. 14 is a schematic illustration of another example of a low profileport assembly.

FIG. 15 depicts one example of a release linear configuration for thedressing illustrated in FIG. 1.

FIG. 16 depicts another example of a release linear configuration forthe dressing illustrated in FIG. 1.

FIG. 17 depicts an example of a release linear configuration for thedressing illustrated in FIG. 1.

FIGS. 18A and 18B are superior and inferior perspective views of anexample of a dressing comprising a carrier layer and multiple releaselayers; FIGS. 18C is a expanded superior perspective view of thedressing in FIG. 18A; and FIG. 18D is a schematic expanded side view ofthe dressing in FIG. 18C.

FIG. 19A and 19B are superior and inferior perspective views of thedressing in FIGS. 18A and 18B following customized shaping.

FIG. 20 depicts an example of the dressing in FIG. 18A with the portmember and conduit.

FIGS. 21A and 21B are superior and inferior schematic perspective viewsof an example of a reinforced dressing.

FIGS. 22A and 22B are superior and inferior schematic perspective viewsof another example of a reinforced dressing.

FIG. 23 depicts another example of a carrier layer configured for usewith the dressing in FIG. 1.

FIG. 24 is a schematic superior perspective view of another example of areinforced dressing.

FIG. 25 is a schematic superior view of still another example of areinforced dressing.

FIGS. 26A and 26C depict one method for sealing the dressing to atreatment site using a liquid sealant.

FIG. 27 is a schematic superior perspective view of a mesh-reinforced,liquid-sealed dressing.

FIG. 28 depicts an example of a liquid-sealing system.

DETAILED DESCRIPTION

Application of reduced pressure to body sites has been shown to betherapeutically beneficial in several applications. One such area is theapplication of reduced pressure to damaged tissue such as chronic woundsin order to accelerate or promote healing. Regardless of the specificapplication area, application of reduced pressure requires formation ofa substantially airtight seal.

In reduced pressure wound therapy (RPWT), a cover structure or dressingcomprising an occlusive cover sheet with an adhesive layer is appliedover the wound, which may be filled with a contact material such asgauze, foam or other porous materials, to provide cushioning anddistribute the reduced pressure throughout the wound bed. The adhesivesheet may serve as a dressing and create a substantially airtightenclosure which encompasses the wound. This enclosure is in fluidcommunication with a reduced pressure source. The reduced pressuresource may comprise an electric vacuum pump, in-wall suction, or anon-electrically powered suction device. The fluid communication betweenthe vacuum source and the occlusive sheet is provided by a conduit whichcommunicates with an opening in the occlusive sheet, or which passesthrough the dressing.

One of the major challenges in delivering RPWT is the application of thedressing and maintenance of a robust seal during treatment. Currenttechniques utilize thin polyurethane adhesive films that can easilywrinkle and fold onto themselves. These films frequently fail to remainairtight for a number of reasons, including mechanical deformationcaused by patient movement and by the reduced pressure itself. Thenature of the films, related to their mechanical characteristics andadhesive properties, make application difficult and time consuming. Inaddition, traditional dressings can be traumatic on removal to thedelicate peri-wound skin and are not configured to treat smallersatellite wound lesions in the immediate peri-wound region of the mainRPWT treated wound. Furthermore, there are locations with particulargeometries that make application of a pre-fabricated dressing difficultand sometimes impractical, such as the bottom of toes.

For example, during the course of operation, reduced pressure applied tothe dressing can lead to buckling of the dressing layer as it is drawndown over the contours to which it is adhered. For example a suctionelement attached to a dressing pulls on the surrounding dressing withapplication of reduced pressure and the contractile forces placed on thedressing can cause the dressing to buckle creating channels that radiateoutward from the suction element attachment area. If these channelsbreach the dressing border, a leak path can form and compromise thedesired seal. Dressing application can also lead to formation ofwrinkles during handling and accommodation of anatomic curvatures.Healthcare practitioners frequently attempt to smooth out thesewrinkles, but the properties of commonly used thin film dressingadhesives do not allow for sufficient filling of channels to close offleak paths that form and can be cumbersome to use. Therefore a needexists for an improved device and method of creating an airtight sealthe wound site to which RPWT is to be applied.

In other general examples in wound care, transdermal drug delivery, andsignal monitoring (i.e. EKGs), among other areas, the effectiveapplication of a dressing-type device or adhesive material to a bodysite may be complicated by the very aspects that lead to a highperformance dressing once it is applied. Namely, pliable materials allowfor a high degree of conformability to various body curvatures.Similarly, dressings that permit a fair amount of stretch accommodatenatural body movement and flexion/extension motions. In combination withan appropriately adherent adhesive, these dressings can successfullystay on the body site for desired durations even under significantvariations in external environmental conditions. Certain transdermaldrug delivery patches, such as that by ORTHO EVRA®, are indicated tostay on for seven day durations while allowing normal daily activitiesas well as exercise including swimming. Successful application of thesedressing systems can be confounded by the pliability that allowsdressings to wrinkle and fold, particularly when the adhesive surfacesare exposed. Adhesive surfaces can often be difficult to separate onceattached. Furthermore, highly stretchable materials may furtherexacerbate the situation because efforts to pull and separate materialfolds often leads to stretching of the dressing itself instead of thedesired separation of self-adhered regions of the dressing. The qualityof the adhesive can make it difficult to apply the desired surface tothe body site as one's fingers may become stuck to the dressing surface.

On the other hand, while the adhesive strength of the dressing may bestrong enough to prevent wrinkling or air channel leaks with movement,if the bond to the underlying skin is too strong, this can result indamage to the underlying skin upon dressing removal. This is especiallytrue for patients with highly friable peri-wound skin which is common inmany wound disorders such as venous stasis ulcers, traumatic wounds,diabetic ulcers, and pressure ulcers. Thus there exists a need todevelop a RPWT dressing that optimizes adhesion for prevention of airleaks, but minimizes trauma from dressing removal to the underlyingskin.

In some embodiments, the adhesive dressing material possesses improvedcrevice and leak channel filling and sealing properties as well asproperties that protect and promote wound healing in the region aroundthe treated wound. The dressing itself may have one or more specificproperties that improve its ability to hold and maintain a seal andprotect the peri-wound skin. Among these properties are (1) increasedthickness of the dressing to facilitate placement and resist wrinklingthat may lead to dressing wrinkling and seal leaks, (2) adhesiongradients on the undersurface of the dressing that allow for maximumsealing while maintaining minimum trauma to the peri-wound skin duringremoval, (3) adhesion strength characteristics that decrease over timeto allow for strong sealing characteristics between dressing changes andeasier and less traumatic removal of the dressing at the time period ofdressing change, (4) a dual seal system with a thicker primary dressingand thinner peripheral dressing and backing system for simplifiedapplication, (5) a breathable dressing that prevents maceration of theunderlying skin, (6) an absorptive dressing that prevents maceration ofthe underlying skin and promotes a moist wound healing environment forskin wounds around the central wound treated with RPWT, (7) supportstructures and thickness design elements that optimize rigidity andwrinkle protection while allowing for dressing conformation to a woundsite, (8) a dressing configured such that upon activation the dressingflows and deforms to the body surface/skin contours to fill in potentialleak channels, (9) a formulation such that the dressing can deformplastically such that stretching the dressing leads to a permanentdeformation in the dressing enabling contouring of complex anatomicalprotrusions and intrusions with minimal elastic energy stored in thedressing layer, (10) a dressing system further configured to havesufficient rigidity to maintain its shape during application whileremaining flexible enough to conform once applied to desired bodytopographies.

In some further examples, the dressing may be configured such that onactivation the dressing flows and deforms to the body surface/skincontours to fill in potential leak channels. The adhesive layer of thedressing may comprise a semi-solid or flowable adhesive material. Someexamples of such adhesives include but are not limited to hydrocolloidor hydrogel materials, silicone, pressure sensitive adhesives, and thelike. In some specific embodiments, the adhesive material may beselected to have a glass transition temperature (Tg) that is at or nearbody core temperature (about 98.6° F.), room, temperature (anywhere fromabout 60° F. to about 90° F.) or body surface temperature (anywhere fromabout 70° F. to about 98° F., for example). In some variations, the Tgmay be in the range of about ±1° F., about ±2° F., ±3° F., about ±4° F.,about ±5° F., about ±6° F., about ±7° F., about ±8° F., about ±9° F.,about ±10° F., about ±15° F., or about ±20° F. within body coretemperature or a surface temperature about 60° F., about 65° F., about70° F., about 75° F., about 80° F., about 85° F., about 90° F. or about95° F. The adhesive dressing in one embodiment is also formulated topossess mechanical properties that allow it to flow and deform to fillpaths or channels that may form during application and subsequenttherapeutic use on a patient. This adhesive material may comprise athicker acrylic adhesive, a hydrocolloid, a hydrogel or other suchadhesive material without limitation. In some examples, the adhesivematerial may have a viscosity in the range of about 5,000 centipoise(cP) to about 500,000 cP, sometimes about 10,000 cP to about 100,000 cP,or other times about 20,000 cP to about 50,000 cP. In other examples,the adhesive material when subjected to low-frequency mechanical input(about <1 Hz) is selected to exhibit deformation properties and wearperformance that may be characterized by a loss angle (tan δ) whichequals the ratio of the loss modulus (viscous component) to the storagemodulus (elastic component) of the tested material may be in the rangeof about 0.5 to about 2, sometimes about 0.5 to about 1, and other timesabout 0.5 to about 0.7.

In one configuration of the device the dressing is made of ahydrocolloid dressing that has some or all of the properties mentionedabove, and/or one or more breathability, moisture absorbent abilities,skin protective properties, and wound healing characteristics. Thisdressing may also provide for a moist wound healing environment and isan appropriate dressing for satellite wound lesions. In one embodiment,the adhesive dressing may be formulated such that it flows onapplication of body heat and/or pressure to the dressing surface toeliminate potential leak channels that may form during application. Inother embodiments, the application of light energy may also initiate asoftening phenomenon to allow the adhesive to flow more readily and fillgaps.

In some embodiments of the sealant system, the film backing on which theadhesive layer resides is formulated to have desirable mechanicalproperties including elastic modulus and maximum elongation and stretchsuch that it is more compliant than the body site tissue it is adheredto in order to mitigate peeling and delamination of the dressing fromthe body surface. Having mechanical properties of the backing andadhesive layer tuned to be less stiff than that of the skin also leadsto improved user comfort as the dressing material will not restrictmovement. It is recognized that skin covering different areas of thebody may have different mechanical properties, and the dressing'selasticity would be such that it would be able to accommodate themaximum possible stretch without applying excessive mechanical force onthe underlying skin during normal distension. The dressing would also beflexible enough to conform to different geometries on the surface of thebody. Some embodiments may be pre-shaped to provide optimal seal aroundirregular geometries such as around the toes or the sacral area.

In some embodiments, the dressing may be formulated to deformplastically such that stretching the dressing leads to a permanentdeformation in the dressing enabling contouring of complex anatomicalprotrusions and intrusions with minimal elastic energy stored in thedressing layer. This stored elastic energy may tend to causedelamination of the dressing; so, its reduction may lead to betteradherence of the dressing. This type of deformational plasticity mightbe highly useful in tailoring the dressing to regions like the foot orsacrum.

While some of the dressing application hurdles have been dealt with byothers, in many cases, application of dressings is desired on differentbody sites. In some instances it is possible to make specific dressingsfor particular body sites to accommodate specific anatomy. However, eventhen, these dressings may not accommodate all anatomic variability andsometimes it is not practical to produce a dressing that will work foreach possible anatomic location. Healthcare practitioners routinely findthat certain dressings as received may not fit the needs of the patientand therefore proceed to cut or shape the dressing to fit the specificcontours and body site requirements of the patient. This need forcustomization becomes particularly apparent with large dressings or bodysurface features with high curvature where folds and wrinkles can makegood adhesion difficult. For transdermal drug delivery, proper adhesiondictates proper therapeutic drug dosing. In the case of signalmonitoring, proper surface contact is critical. For RPWT, the quality ofthe seal around a wound site may be beneficial for maintenance of thereduced pressure, and leak paths can compromise therapeutic efficacy.The sealing properties of this dressing may be especially beneficial forRPWT devices that do not use a continuous electric pump or similarreduced pressure generation system, or otherwise have a limited suctioncapacity, as the tolerances for significant leaks is much lower thantraditional RPWT devices. In many dressing systems, the dressingstructures, such as release liners or handling flaps that permit easierapplication lose their functionality if the dressing must be shaped tofit a certain contour. Disclosed herein is a sealant system and methodthat mitigates formation of leak paths during and after application ofsaid dressing by reducing folding of the dressing and adhesion of thedressing to itself or user while allowing simple dressing application tofit the needs of the individual after being cut to shape whilepossessing characteristics that permit the dressing adhesive tosubsequently fill and close off channels that may form during or afterthe dressing application.

In addition, many wounds that may be treated by RPWT may havesurrounding satellite wounds that are smaller and distinct from thecentral wound treated with RPWT. For example, patients with venousstasis ulcers often present with clusters of open skin areas. Inaddition, some wounds heal by skin bridging from epidermal migrationacross the wound. When this occurs, smaller proximal wounds can developthat are more near healing than other regions of the original wound.These types of satellite wounds may be too small to treat with RPWT, butmay lie within the boundaries of where the dressing must cover to createa seal. Furthermore, many wounds are surrounded by highly friable anddelicate skin that can be injured during frequent adhesive dressingremoval. Traditional RPWT dressings do not address the needs of thisperi-wound skin and satellite lesions, and there exists a need todevelop a dressing that is both gentler to the peri-wound skin and maytreat these satellite lesions with an appropriate dressing that promoteswound healing.

Furthermore, there are wounds that are located in regions of the bodythat using any type of pre-fabricated film would be difficult to apply.These regions might include wounds on the toes or fingers. Thus, thereneeds to be a dressing that can provide adequate sealing in theseregions that can be tailored to the specific geometries of theselocations.

The passage through the dressing is often times facilitated by a portfeature on the top surface of the dressing. In the prior art, this portfeature is fixed relative to dressing, which fixes the directionalorientation of the fluid communication conduit once the dressing isadhered. In many applications, it may be advantageous to re-orient thefluid communication conduit direction after application of the dressing,since the user needs to account for the position and direction of thefluid communication conduit prior to and during application of thedressing. There exists a need for a port which allows re-orientation ofthe fluid communication conduit after application of the dressingwithout disrupting the dressing.

Wound drainage (e.g. exudates) is often times evacuated from the woundtowards the reduced pressure source during the course of treatment ofRPWT. If reduced pressure is interrupted or terminated, this drainagepotentially may flow back into the wound, especially if the interruptedor terminated reduced pressure source is located at a higher elevationthan the wound. Wound drainage may be contaminated with infectiousmicrobes or compounds which are deleterious towards wound healing.Therefore, there exists a need to prevent wound drainage from flowingback to the wound in case of terminated or interrupted reduced pressure.

Use of a substantially opaque or aesthetically appealing dressing forRPWT may be advantageous, since it hides the wound and wound contactmaterial from sight and may increase the psychological comfort of thepatient and others. In some instances, it may also be advantageous touse a substantially transparent dressing, since clinicians may wish toinspect the wound, wound contact material or peri-wound skin withoutremoving the dressing. Disclosed herein is a dressing which shields thewound from view normally, but also allows inspection under the dressing.

RPWT traditionally requires maintenance of reduced pressure at the woundbed for extended periods of time. It may be advantageous to have anindicator to show whether reduced pressure is present in the system orhas been compromised, for example by a leak in the dressing. This may beparticularly beneficial with closed system vacuum sources. Pressureindicators may include instrumentation such as dial indicators andpressure transducers. Often times, these may be large, bulky, requireelectricity or are expensive. Furthermore, often times, these indicatorsare located at the reduced pressure source and do not provide indicationof the pressure at the site of the wound bed where its pressureinformation may be more useful. In case of disruption or clogging of thefluid communication conduit between the reduced pressure source and thedressing, these indicators may not detect that reduced pressure may belost at the wound site but still present at the reduced pressure supply.There exists a need for a simple, inexpensive indicator to informclinicians or patients whether reduced pressure is present at the woundor not.

Some of the wounds being treated with RPWT may be present due to tissueischemia from pressure applied to a body site, e.g. decubitus wounds orpressure sores. To prevent or otherwise reduce the risk of continueddegradation of the wound region and surrounding tissue, a low profilereduced pressure conduit that reduces concentration of force on thewound or surrounding tissue may be beneficial for proper therapeuticdelivery of reduced pressure and for better wound healing. Current RPWTconduits often contain elements that can create additional pressurepoints over a wound if a load were to be applied onto the port componentof the conduit. Disclosed herein is a negative pressure conduit that islow profile as to reduce the development of pressure points on the woundor surrounding tissues.

Disclosed herein are some embodiments of a device which enhance thefunctionality and/or usability of delivery of reduced pressure to bodysurfaces. One embodiment comprises a dressing, a fluid communicationconduit and a port which allows passage of the fluid communicationconduit from one side of the dressing to the other. The dressing maycomprise at least one adhesive side which in practice may be adhered toa body surface to create a substantially airtight seal. The dressing anddressing adhesive may comprised polyurethane, hydrocolloid, hydrogel,silicone, acrylic, any other material or any combination thereof knownin the art.

In some embodiments, the port is configured to allow at least somefreedom of rotation around the axis substantially parallel to the planeof the dressing. In some embodiments, the freedom of rotation isprovided by an o-ring seal and flange and groove system. In someembodiments, the port body comprises a substantially compliantelastomeric material bonded to substantially rigid elements whichinteract with substantially rigid elements on the dressing whichtogether provide for substantially airtight seal of the rotationalelements of the port. The port member may further comprise a connectorconfigured to facilitate coupling to a fluid communication conduit thatis then attached to the vacuum source. In other embodiments, at least aportion of the conduit may be integrally formed with the port member.

In some embodiments, the fluid communication conduit and/or port memberpasses through or transects the dressing and connects a sealed enclosureformed by the dressing with a reduced pressure source. In someembodiments, the fluid communication conduit comprises the port andtubing. In some embodiments, the tubing comprises a single lumen, whilein other embodiments, the tubing may comprise multiple lumens.

In some embodiments, a one way flow mechanism may be interposed alongthe length of the fluid communication pathway between the dressing andthe vacuum source. In some mechanisms, the one way flow mechanism islocated in or integrated into the body of the port member, while in someembodiments, the one way flow mechanism may be integrated into thedressing or port-dressing interface. In still other embodiments, the oneway flow mechanism may be located in or integrated into the tubing. Insome embodiments, the one way flow mechanism may prevent or reduce thedegree or risk of backflow of wound drainage collected by the reducedpressure source back to the wound. In some embodiments, the one way flowmechanism may be a one way valve, such as a duckbill valve, a slitvalve, a spring valve, an umbrella valve or any other suitable one wayvalve known in the art. In some embodiments, a plurality of one way flowmechanisms may be interspersed throughout the fluid communicationconduit. In further embodiments, the one way flow mechanisms may havenon-uniform opening or cracking pressures to account for fluid pressuredifferentials from pressure head or flow rate.

In some embodiments of the device, the load concentration of the reducedpressure conduit and/or port member may be reduced during load bearingsituations by reducing the height of the port and increasing its width.Reduction of load concentrations or pressure points may be furtherprovided by the use of softer materials such as silicones or othermaterials known in the art to be able to deform under load. Thesematerials may further be configured to possess similar mechanicalproperties as the skin such as durometer and elastic modulus. In someembodiments, the conduit in the port between the wound site and thetubing or reduced pressure source is reinforced with supports thatprevent collapse of the conduit. In some embodiments, these supports arefurther configured to distribute loads applied to the device surface toreduce pressure concentrations. In some configurations of the device,the total cross-sectional surface area may be maintained relative to around tube, but the height of the tubing (and thus nozzle) may bereduced by making the diameter wider and flatter to distribute loadsmore evenly. In addition, in certain configurations a multi-lumenconduit may be used to further reduce the external diameter and lowerthe profile of the nozzle and tubing.

In further configurations, the reduced pressure conduit may beintegrated and potentially molded directly into the dressing material.In further embodiments, the reduced pressure conduit may be positionthrough one or more openings or fenestrations of the dressing. In afurther embodiment, the fenestration provides an insertion opening foran attachment port to connect a source of reduced pressure, or toconnect an extension tube located on the outer surface of the dressing.In one embodiment, the reduced pressure conduit comprises a plurality ofsuch fenestrations.

In one embodiment, the reduced pressure conduit or tubing comprises ahollow tubular structure which flares into and joins with the dressingmaterial, enabling fluid communication between the volume beneath thebottom surface of the dressing and interior of the tubular structure. Inone embodiment, the reduced pressure conduit is a resilient conduitembedded within the dressing with terminals connecting the bottomsurface of the dressing and an attachment port on a side edge of thedressing. In one embodiment, the reduced pressure conduit is a series ofsuch conduits.

In some embodiments, the reduced pressure conduit comprises a mechanismwhich allows quick attachment and detachment of the tube or reducedpressure source in an airtight manner.

In one configuration of the dressing, the dressing is integrateddirectly with the reduced pressure source and wound enclosure, e.g. avacuum source attached directly to a port without an extension tube, andmay also comprise further attachment of other portions of the vacuumsource directly to the dressing to resist swinging or other motions ofthe vacuum source relative to the dressing. This eliminates may alsoreduce the need to puncture a hole and attach the vacuum source to thedressing, as required in some dressings, thereby mitigating applicationcomplexity, enabling successful application by non healthcareprofessionals and eliminating another potential source of air leak. Inthis configuration, the vacuum source does not employ tubing, butdirectly integrates into the dressing.

In some embodiments of the disclosed invention, the fluid communicationconduit and/or the port member comprises a reduced pressure indicator.In some embodiments, the reduced pressure indicator is located in oralong the conduit tubing. In some embodiments, the reduced pressureindicator is located within the port. In some embodiments, the reducedpressure indicator is integrated into the body of the port. In someembodiments, the reduced pressure indicator is comprised of a compliantmaterial which visibly deforms when a pressure gradient is appliedacross it. In some embodiments, the pressure gradient leads a colorchange to indicate that the proper level of pressure application isachieved. For example, a sufficiently translucent or transparent blueelement in proximity to a yellow material with the application ofreduced pressure can effect a color change and appear green to indicateapplication or non-application of reduced pressure.

Various examples of the above embodiments are provided in greater detailbelow.

FIG. 1 depicts one embodiment of a reduced pressure treatment system100, comprising a cover structure or dressing 101 that may be attachedto a vacuum source (not shown). The dressing 101 may comprise aflexible, adhesive sheet which may be placed over a body surface.Dressing 101 may further comprise release liners, carrier films or otherfeatures known in the art to facilitate application of the system 100 toa treatment site. Examples of the release liners and carrier films areprovided in greater detail below. The dressing may comprise any of avariety of suitable sheet materials, including but not limited topolyurethane, silicone, vinyl, polyvinyl chloride, polyisoprene, latex,rubber, thermoplastic elastomers, hydrogels, hydrocolloids, and thelike. In some examples, the stiffness of the sheet material may be inthe range of about 59 N/m to about 138 N/m for a 25.4 mm wide specimen,sometimes about 19 N/m to about 59 N/m, and other times about 3 N/m toabout 19 N/m. The sheet material may be optically transparent ortranslucent, or may be opaque. The sheet material may have a uniform ornon-uniform thickness. In some examples, the sheet material may have anaverage thickness in the range of about 0.05 mm to about 2 mm or more,sometimes about 0.1 mm to about 1 mm, and other times about 0.3 mm toabout 0.5 mm, exclusive of any adhesive or other supporting structures.In examples wherein the sheet material comprises a non-uniformthickness, the sheet material may comprise an edge region with reducedthickness relative to an interior region with an increased thickness.The transition between the reduced and increased thickness regions maybe smooth or angled, and in some variations, three, four, five or moreregions of different thicknesses may be provided. In other examples, theregions of reduced and increased thicknesses may be arranged in otherconfigurations, such as those depicted in FIGS. 24 and 25, which aredescribed in greater detail below. In some variations, the sheetmaterial may be attached or embedded with other reinforcementstructures, or may comprise a woven or braided sheet configuration. Thesheet material may be manufactured in any of a variety of shapes, andmay be further cut or shaped during manufacturing, or at thepoint-of-use, to another shape and/or size. The shapes include but arenot limited to circles, ellipses, ovoids, squares, rectangles,trapezoids, triangles, arcuate shapes, starburst shapes, and the like.The corners of the shape, if any, may be rounded or angled.

The dressing 101 also further comprises an adhesive layer located on thelower surface 107 of the dressing 101. In some embodiments, thethickness of the adhesive may be increased to facilitate placement andresist wrinkling that may lead to dressing wrinkling and seal leaks. Inone embodiment of the dressing, the adhesive dressing thickness isincreased to thicknesses substantially in the range of about 300 micronsto about 10,000 microns or more, sometimes about 500 microns to about2000 microns, and other times about 500 microns to about 1000 microns.Typical dressings used for RPWT may utilize thin relatively inelasticpolyurethane film backings or facestock on the order of about 25 micronsto about 50 microns in thickness with acrylic adhesive layers on theorder of about 25 microns to about 125 microns in thickness. Thesethicknesses are demonstrably not sufficient in practice to easily createair-tight seals that last for about 4 to about 7 days. These thinnerdressing may produce air leaks more often than when dressings withthicker adhesives were utilized. In addition, wrinkling with applicationof the thicker dressing was also reduced due to the increased rigidityafforded by the dressing thickness.

In some further examples, the adhesive layer material may be selected toprovide an initial 90°-peel release force in the range of about 5 N to18 N for a about 25 mm wide specimen. In some variations, the releaseforce may be in the range of about 0.2 N/mm to about 1.5 N/mm, sometimesabout 0.4 N/mm to about 1 N/mm, and other times about 0.5 N/mm to about1.2 N/mm. The procedure for measuring the release force may be astandardized procedure, such as ASTM D3330, or other appropriateprocedure. The adhesive layer may also be selected to provide a probetack force property in the range of about 2.75 N to about 5 N with aninitial loading of about 100 kPa, or other times in the range of about 2N to about 6 N. The probe tack force may also be measured usingstandardize procedure, such as ASTM D2979, or other appropriateprocedure. In some further embodiments, the adhesive layer may beselected to exhibit a decreased release force of about 20%, about 30%,about 40%, or about 50% or higher over a period of about 24 hours, about48 hours, about 72 hours, or about 96 hours. In some instances, areduced adhesive force over time may facilitate periodic dressingremoval while reducing adhesive related damage to the surrounding skin.

In additional embodiments, fluid absorption of the dressing may beincreased with adhesive material selection and thickness. For example,in some embodiments the dressing is composed of a hydrocolloid. In someexamples, a different skin adhesive is provided around the edge orperiphery of the dressing, while a hydrocolloid layer is provided on theinterior region of the lower surface of the dressing. In other examples,however, the hydrocolloid may function both as a fluid absorption layerand an adhesive layer. The compositional properties and increasedthickness of the dressing adhesive element allow for more capacity tohandle fluid absorption, which may be beneficial in having a dressingthat is functional in the presence of wound exudates and additionallypromotes wound healing by maintaining a moist environment.

The dressing system may also comprise adhesion strength gradients on theundersurface of the dressing. In some examples, adhesive with higherbonding strength at the periphery of the dressing is provided comparedto the central portion of the dressing. This is particularly importantfor RPWT treated wounds with fragile surrounding skin or smallerperipheral satellite wounds. Since the central portion of the dressingmay be closest to the RPWT treated wound, the lower adhesive bondingproperties of the central portion of the dressing may be less traumaticupon removal to the more delicate peri-wound skin and satellite lesions.The increased adhesive strength along the periphery may serve tomaintain the integrity of a seal in a non-limiting manner by mitigatinglifting of dressing edges, disruption from moisture (i.e. sweat,bathing, etc).

In further embodiments, a dressing with adhesion strengthcharacteristics that decrease over time is disclosed to allow forsufficient sealing characteristics between dressing changes and easierand less traumatic removal of the dressing at the desired time ofdressing change. In some embodiments, the dressing adhesive may havedecreased bonding strength over time to allow for maximum adhesionduring the period of treatment with RPWT between dressing changes, butweakened adhesion at the time of dressing change (typically in about 3to about 7 days). This again allows for lesser trauma to the peri-woundskin during treatment. In some embodiments, the dressing is ahydrocolloid dressing that has weakening bond to the underlying skinwith water absorption overtime. An indicator in the dressing may furtherindicate when the dressing should be removed and/or replaced. Inadditional configurations, the adhesive element may be deactivated orweakened with temperature, moisture, light, solution or other relatedmodality that can weaken adhesive bonding.

A dressing with a thicker central dressing and a thinner peripheraldressing and backing system for simplified application is alsodisclosed. In this embodiment, a two seal system may be implemented tomitigate air leaks that may occur from the dressing to the wound bed inwhich a thicker dressing is bordered by a thinner dressing that extendsaround the edges of the dressing to create a secondary seal. In someembodiments, the central dressing may be made of a thicker hydrocolloiddressing and the peripheral dressing is a thinner polyurethane borderwith a stronger adhesive profile than the central hydrocolloid portion.The thinner peripheral second seal may help create a more resilient sealbecause the thinner portion of the dressing is less likely to curl orbecome mechanically disrupted than the thicker central portion. Bycombining the thicker and thinner dressings into a single dressing, thedisclosed dressing captures the advantages of the thicker dressing asdescribed above without the disadvantage of dressing edge curling andincreased susceptibility to mechanical disruption. In addition, thesecond peripheral thinner dressing creates a second seal around thedressing that further mitigates the risk of air leaks in the dressingsystem. The use of adhesion gradients with the two seal system allowsfor robust seal at the edges with less traumatic removal to theperi-wound skin as well. In some embodiments, the dual-sealant systemmay possess two adhesive release liners. First, the central adhesiverelease liner is removed, and the dressing is placed on the patient.Next, the second release liner for the outer layer dressing, in someconfigurations a strip of liner along the dressing border, is removedafter the central portion is adhered to create a secondary seal. In someembodiments, the double dressing has a peripheral portion of thedressing having a higher adhesive property than the central portion ofthe dressing to prevent the edges of the thicker central layer fromcurling up while minimizing trauma to the peri-wound skin.

An absorptive dressing is further disclosed that prevents maceration ofthe underlying skin and promotes a moist wound healing environment forskin wounds around the primary wound treated with RPWT. Disclosed hereinis a RPWT dressing with moisture absorbent properties that augmentswound healing conditions by reducing moisture build-up at the peri-woundskin and satellite lesions around the main lesion being treated withRPWT. This dressing in some embodiments is a hydrocolloid dressing ordressing with similar characteristics as a hydrocolloid. In somevariations, the hydrocolloid layer (or other moisture absorbentmaterial) may have an absorbency rate of about 900 grams/m²/day, about1000 grams/m²/day, about 1100 grams/m²/day, about 1200 grams/m²/day, orabout 1500 grams/m²/day or higher. The advantages of using an absorptivedressing as a dressing are that it can prevent maceration of theunderlying skin, it is in contact with, and it can act as a good wounddressing for satellite lesions without the need for other secondarydressings underneath the dressing. In this embodiment the dressingitself may serve as the dressing for the peri-wound skin and peri-woundsatellite lesions. The adhesive dressing disclosed in some embodimentsmay also contain therapeutic agents including drugs that facilitatehealing or antimicrobial agents such as silver. One of the principles ofmodern wound therapy is the benefit of maintaining a moist wound healingenvironment. Thus, dressings for wounds that maintain a moist woundhealing environment have become the mainstay of treatment for many typesof wounds. Dressing such as alginates, hydrocolloids, and foams, allhave absorptive properties that optimize the moisture levels of theunderlying tissue for healing. Traditional RPWT dressings are notoptimized for promoting healing of fragile peri-wound skin and satellitelesions. If the environment under the dressing near the underlying skinor satellite wounds is wet, it can lead to maceration of the underlyingskin and wound edges. If the wound environment is dry, it can lead tosuboptimal wound healing. A moist wound environment may be provided bymoist gauze or other moist wound contact material. In some examples, themoist gauze is used in combination with a hydrocolloid dressing toprovide a moist wound environment while wicking away moisture from theperi-wound skin.

A breathable dressing is disclosed that prevents maceration of theunderlying skin. In some embodiments, the dressing will be configured tohave a high enough moisture vapor transfer rate (MVTR) to allow forvapor loss that minimizes fluid collection over the peri-wound skin andthe development of maceration of the underlying skin while at the sametime maintaining a sufficiently strong seal to deliver RPWT. In oneembodiment, the dressing comprises a hydrocolloid layer with anincorporated breathable component or construction. The hydrocolloidlayer may be paired with a cover material that is also configured towick away moisture, and in some variations, may have a MVTR of about 900grams/m²/day, about 1000 grams/m²/day, about 1100 grams/m²/day, about1200 grams/m²/day, or about 1500 grams/m²/day or higher. In someembodiments, the combination of moisture absorption and MVTR afford thedressing the ability to maintain desirable moisture content at the woundbed while reducing maceration and damage of peri-wound skin. In otherexamples, the dressing may comprise a single layer of hydrocolloid orhydrogel.

In some examples, the adhesive layer may be configured to mitigate painand discomfort encountered by patients during the placement andreplacement of reduced pressure therapy dressings. Damage to underlyingtissue may also be reduced. The dressing may comprise an adhesivecoating that creates bonding that is amenable to softening through achemical reaction caused by application of a removal solution or hotair. In another embodiment, the adhesive coating may comprise a resinthat softens when irradiated with ultraviolet (UV) radiation. Examplesof a UV-softening adhesive include adhesives that have a bond which isbroken by irradiation of an ultraviolet ray, such as CH, CO(ketone),CONH(amide), NH(imide), COO(ester), N=N(azo), CH=N(Schiff) and the like.An adhesive predominantly containing such a bond may be employed, forexample a polyolefin adhesive such as a polyethylene adhesive or apolypropylene adhesive, a polyimide adhesive, a polyester adhesive, apolymethylmethacrylate (PMMA) adhesive and on the like. Also, anadhesive containing aromatic hydrocarbons (one or a plurality of benzenerings, or a fused ring thereof) in its structural formula may beemployed. For example, some examples may employ an adhesive of apolyphenylenesulfide (PPS) adhesive, or of a polyethersulfone (PES)adhesive. Also, one or a combination of two or more of these materialsmay be employed. These adhesives may improve patients' quality of lifeas pain and re-injury during dressing changes would be mitigated andtreatment time may be shortened. Finally, the adhesive coating may bepressure sensitive or otherwise formulated to permit long term robustadhesion to skin.

The treatment system 100 may further comprise a port 102 coupled totubing 103 that provides a fluid communication conduit from underneaththe dressing 101 towards a reduced pressure source (not shown). Port 102may comprise compliant materials and a low vertical profile. In someexamples, the low vertical profile comprises a maximum perpendiculardimension to the sheet material 101 that is smaller than a maximumtransverse dimension to the maximum perpendicular dimension, anoptionally transverse to the longitudinal axis of the tubing 103. Insome examples, the maximum transverse dimension may be twice, threetimes, four times, five times, or six times or more greater than themaximum perpendicular dimension of the port 102. In examples wherein theport is integrally formed with the dressing materials, these dimensionsmay be measured from the plane aligned with the upper surface of thedressing.

In some examples, tubing may be attached or separated from the portusing a connector fitting located on the port. The fitting may beconfigured to accept a cut tubing end, or may be configured to attach toa complementary end connector fitting that is attached to the tubing. Instill other examples, the tubing may be integrally formed with the port.In still other examples, all or a portion of the port may further beconfigured to be detached and reattached to the dressing.

As depicted in FIG. 1, in some examples, tubing 103 may further compriseone way flow mechanism 105. In some examples, the one way flow mechanismmay reduce the risk of contaminated wound aspirate to backflow back intothe wound. The one way flow mechanism may also permit detachment of thevacuum source without backflow of gas back into the treatment site. Asmentioned previously, in some examples, multiple one way flow mechanismsmay be provided along a flow pathway. In other embodiments, one way flowmechanism may be incorporated into port, or the vacuum source attachedto the one way flow mechanism.

FIG. 2 is a schematic cut-away view of the port 102 and one way flowmechanism 105 depicted in FIG. 1. As shown, the one way flow mechanism105 may comprise a valve 203 encased in housing 202 which is interposedin tubing 204. Valve 203 as depicted in FIG. 2 is a duckbill valve, butin other examples the flow mechanism 105 may comprise other valvespreviously mentioned or any other valve known in the art. Valve 203 maybe oriented such that forward flow 205 of material is permitted towardsthe reduced pressure source. Forward flow 205 may comprise wounddrainage fluids (exudates) or other material which is desirous toevacuate toward the reduced pressure source. In case reduced pressureapplication is terminated or interrupted, backward flow 206 of materialmay occur towards the port 102, but may be prevented or reduced by theone way flow mechanism 105.

Referring to FIG. 1, in some examples, the port 102 may comprise a portassembly that permit partial or full rotation of movement relative tothe dressing 101. Here, port 102 is configured to with a range ofrotational motion 104 around a rotational axis 108 that is generallynormal to the plane of the dressing 101. Movement of the port mayfacilitate placement of the dressing 101 and/or securing the vacuumsource. Port motion may also reduce the risk of kinking of the tubing103, or transmission of torsional forces between the vacuum source andthe dressing, which may improve patient discomfort or reduce the risk ofdressing separation from the treatment site. FIGS. 3A and 3B depict oneexample of a rotatable port assembly 301. Port assembly 301 comprises abase or collar member 305 that is adhered or attached to the uppersurface 315 of the dressing 304 at a lower plate or flange 323, but inother variations, the collar member may be adhered or attached to thelower surface 317 of the dressing 304, or both surfaces 315 and 317.Port assembly 301 further comprises a port body 309 that attaches to thecollar member 305. The collar element 305 and the port body 309 maycomprise flexible, semi-flexible or rigid materials. In some variations,the collar element 305 may comprise a material that is more rigid orotherwise has a greater durometer than the material comprising the portbody 309. An opening or fenestration 308 through dressing 304communicates with a lumen 321 of the collar element 305. The collarelement 305 further comprises a rotational axle 319 that comprises acircumferential ridge 306 and an o-ring 307. When the port body 309 iscoupled to the collar element 305, the rotational axle 319 is retainedin a port cavity 325 by a port flange 327 that forms an interfit betweenthe circumferential ridge 306 and the lower flange 323. The lumen 321 ofthe collar element 305 provides fluid communication between thefenestration 308 of the dressing 304 and the port cavity 325 at anyangle of the port body 309. In other examples, the lumen of the portassembly may be configured as a side lumen whereby certain angularpositions of the port body may seal off the lumen, thereby permittingthe rotation of the port body as an open/close valve.

In the example depicted in FIGS. 3A and 3B, the tubing element 312 ismay be bonded or glued or otherwise permanently sealed to the port body309. In other variations, however, the port body may comprise a recessedor projecting flange configured to sealably insert into the lumen of atube. The port body may be configured to attach to the tubing at any ofa variety of angles relative to the plane of the dressing. In thedepicted embodiment, tubing element 312 is directed parallel to plane ofdressing 304. In other embodiments, tubing element 312 may directed atany angle between about 0 degrees and about 90 degrees relative todressing 304, or may comprise at least partial rotational degree offreedom which allows alteration of angle between tubing element anddressing in the range of about 0 degrees to about 90 degrees. Ananti-kink structure may be provided on the port body or the tubing toresist kinking of the tubing at the port interface. In some variations,port body 309 may further comprise compliant or elastomeric materials,and may also comprise a reduced pressure indicator as described later.The port body 309 may further comprise a sleeve element 310 within theport cavity 325, configured to form a complementary interfit with therotational axle 319. The sleeve element 310 may further comprise acircumferential groove 311 configured to accept the ridge 306 of thecollar element 305. This may improve the sealing characteristics betweenthe collar element 305 and the port body 309 by providing a longertortuous pathway for gas to escape. The sleeve element 310 may alsoresist tilting movement of the port body 309 and the collar element 304,thereby providing additional stability that may further comprise radialgroove 311 but is configured to permit rotation of port body 309relative to dressing 304 along axis 313 substantially normal to dressing304. When port 301 is assembled onto dressing 304, o-ring 307 may forman additional seal against sleeve element 310. As mentioned previously,port body 309 may further be configured to be simply detached andreattached to the substantially rigid collar element 305.

FIGS. 6A and 6B depict an optional feature of the port 600, comprising areduced pressure indicator mechanism 601. The pressure indicator 601 maycomprise a flexible membrane or a thinned region of the wall of the portbody surrounding the port cavity, which is configured to substantiallycollapse or inwardly deform in the presence of a reduced pressure withinthe port (or port cavity of the port body). The degree of deformation ata particular relative level of reduced pressure may be tailored byvarying the thickness of the flexible material or the type of flexiblematerial. The indicators 601 may comprise the same or different materialas the other portions of the port 600. FIG. 6A depicts port 600 in theabsence of reduced pressure within the port 600, while FIG. 6B depictsthe collapse of the pressure indicator 601 due the pressure differentialbetween the higher atmospheric pressure and the reduced pressure withinthe port 600. Port 600 undergoes deformation 602 due to pressuredifferential, which visibly indicates the presence of reduced pressure.In some further example, color change materials that change color withmechanical deformation may be used for the pressure indicator 601. See,for example, the color change material described in U.S. Pub. No.2006/0246802, which is hereby incorporated by reference in its entirety.

FIGS. 7A and 7B, illustrate another embodiment of a port 700 comprisinga reduced pressure indicator 702. FIG. 7A depicts port 700 in an absenceof reduced pressure, and FIG. 7B depicts port 700 in the presence ofreduced pressure. The exterior wall 701 of port 700 is comprised oftranslucent, compliant material. Interior to the wall of port 701 is anempty volume 705 of air in fluid communication with a source of reducedpressure. Under application of reduced pressure, air in cavity 705 isevacuated, which causes a movable wall 701 of port 700 to collapsetowards an inner wall or the floor 707 of port 700. Floor 707 furthercomprises one or more visually distinctive regions 706. In the absenceof reduced pressure 702, the translucency of the wall 701 of port 700obscures the visually distinctive regions 706. Under the presence ofreduced pressure, the wall 701 of port 700 is biased towards floor 707and contacts with distinctive regions 706. Direct contact 704 withdistinctive regions 706 may cause distinctive regions 706 to become morevisible through translucent wall 701 material. In some embodiments,distinctive regions 706 comprise regions of color or pigment. In someembodiments, distinctive regions 706 comprise symbols or patterns. Insome embodiments, distinctive regions 706 may comprise text.

FIGS. 8A and 8B illustrate another embodiment of a reduced pressuretreatment system 800 comprising a reduced pressure indicator 801. FIG.8A and 8B depict the reduced pressure conduit (e.g. the port 802 and thetubing 803) in absence of reduced pressure, in the presence of reducedpressure, respectively. The elastomeric material element 804 of thereduced pressure indicator 801 remains in an open or expandedconfiguration without the application of reduced pressure. In thepresence of reduced pressure, the air in the elastomeric cavity 805 isevacuated through the communication openings 806 in the reduced pressureconduit tubing changing the configuration to a “sucked down” orcollapsed configuration, where the elastomeric material of the indicatoris pulled against the tubing. Although FIGS. 8A and 8B depict thepressure indicator 801 as having four communication openings 806, inother variations, the openings may number from about one to about twentyor more openings, sometimes about four to about sixteen openings, andother times about eight to about twelve openings. Direct contact of theelastomeric material with the tubing provides a physical and visualindication of reduced pressure. Direct contact may cause the outersurface of tubing 803 in the cavity 805 to be more visible through theelastomeric material 804 when the material is transparent ortranslucent. In some embodiments, the tubing in the indicator enclosurecomprises regions of color or pigment. In some embodiments, the tubingin the indicator enclosure comprises symbols. In some embodiments, thetubing in the indicator enclosure comprises text. Although theelastomeric material 804 in FIGS. 8A and 8B comprises a sleeve ortubular shape that is adhered to the tubing 803 at the tubular ends 806of the material 804, in other examples, the elastomeric material maycomprise a sheet or cup-like structure adhered around its perimeter tothe tubing 803. The elastomeric material 804 may be a silicone,polyurethane, and the like, and may be the same or different materialthat comprises the tubing 803.

FIG. 9A illustrates a fluid communication conduit 900 comprising a lowprofile port 901 and low profile tubing 902 that has a reduced height903 relative to an increased width 904. In some examples, the height 903may be in the range of about 0.5 mm to about 30 mm, sometimes about 2 mmto about 15 mm, and other times about 4 mm to about 8 mm, while thewidth 904 may be in the range of about 0.5 mm to about 50 mm or more,sometimes about 4 mm to about 30 mm, and other times about 10 mm toabout 15 mm. In some examples, the port may have a width to height 901aspect ratio greater than 1:1 to reduce focal pressure concentrationrelative to ports having generally 1:1 ratios. The width to height ratiomay be in the range of about 3:2 to about 20:1 or more, sometimes about2:1 to about 10:1 and other times about 3:1 to about 6:1. The aspectratio in the multi-lumen tubing 902 may be achieved using either anon-circular lumen or a configuration comprising multiple lumens 905, asshown in FIG. 9A. The opening 906 in the port 901 may be a singleopening 906 that is in fluid communication with each of the multiplelumens 905. In other variations, each of the multiple lumens may havetheir own port opening. A web, membrane or other interconnectingstructure 907 may be provided between the multiple lumens 905, but maybe omitted in other variations.

The flexible multilumen tubing 902 is shown to be lower profile and topermit alternate channels of reduced pressure communication with thewound and removal of exudates. The port material and tubing may be madeof one or more compliant materials such as silicone or otherthermoplastics elastomers (TPEs) known to those in the art that aremoldable, extrudable or otherwise formable. In some variations, due tothe smaller lumen diameters, capillary resistance may significantlyimpact the movement of liquid materials through the port and/or tubing.To reduce these surface interactions, the port and/or tubing may betreated with a lubricious coating, and/or may undergo surfacemodification procedures to alter the hydrophilicity or hydrophobicity ofthe native port or tubing materials. Such procedures are well known inthe microfluidics area. To facilitate standardized connections tovarious vacuum sources, a multiple lumen to single lumen adapter orconnector 908 may be provided to attach to regular tubing 909. Theconnector 908 may also be integrally formed with the multiple lumens 905and/or the regular tubing 909.

FIG. 12 depicts another example of a reduced pressure treatment device1200 comprising a port member 1201 with an elastomeric membrane pressureindicator 1202 attached to a dressing 1205. In this example, the tubingattachment portion or connector 1203 of the port member 1201 issurrounded by a radial section 1204 of elastomeric membrane whichdeforms under pressure.

FIGS. 10A to 10D illustrate one example of the interior structure of alow profile port 1000, having a reduced height 1001 relative to itswidth 1002. In some example, with a reduced height 1001, the port cavity1003 may or may not be at greater risk of collapse or closure,especially when manufacturing using a flexible material. To resistcomplete collapse, the cavity 1003 may comprise integrated supports 1004to distribute loads and maintain cavity or conduit patency by preventingore resisting collapse of the port walls 1005 and to maintain at leastsome patency with the port opening 1006 to the wound bed 1007 and thetubing 1008. Examples of various configurations for the low profiletubing 1008 are depicted in FIGS. 10C and 10D. In FIG. 10C, multiplelumens 1009 may be separated by lumen support walls 1010 that span fromone internal surface to another, while in FIG. 10D, partial supportwalls 1011 located within and projecting into a single, non-circularcommon lumen 1012 are provided. The different support structureconfiguration may be used to distribute loads and may reduce or preventcollapse of the tubing structure when loaded.

FIG. 11A depicts another example of a low profile treatment device 1100with low profile tubing 1101 directly integrated into the dressing 1102itself. Unlike prior examples, the integrated tubing 1101 is attached tothe dressing 1102 all the way to an outer edge 1103 of the dressing1102. In other examples, the attachment of the tubing to the dressingmay terminate anywhere in the range of about 1 cm to about 4 cm from thedressing edge, sometimes about 0.5 cm to about 3 cm, and other timesabout 0 cm to about 2 cm. To reduce the risk of the tubing 1101 snaggingon clothing or other items, sloped edges 1104 may be provided.Integrated supports 1105 may be provided (FIG. 11C) to further help todistribute load bearing and/or maintain patency of the lumens 1106, butin other examples (FIG. 11B), the flat configuration lumen 1107.

FIG. 13 depicts another example of a reduced pressure treatment device1300, comprising a dressing 1301 with a gasket or sealed junction 1302through which low profile tubing 1303 passes through to an integratedsuction port 1304. An air-tight junction permits the port to sit belowthe dressing and exit through the layer to the reduced pressure source.In this example, the port opening 1305 may directly communicate with thetreatment cavity formed between the treatment site and the dressing. Inother examples, the dressing may be a multi-layer sealing layer and theport may be located between two or more layers. In still other examples,the port may not be directly attached to the dressing 1301 but ispermitted to pivot and/or translated through motion between the tubingand the sealed junction 1302 of the dressing 1301.

FIG. 14 depicts another example of a treatment device 1400 comprising asealed junction 1401 and a low profile tubing 1402 passing therethrough.In the examples, the distal end 1404 of the tubing 1402 is not attachedto a port or suction head and may be customized in length to terminateat a desired location relative to the dressing 1403. In thisconfiguration, both the dressing and reduced pressure conduit can beshaped (e.g. cut) to desired the geometry for a wound site. In somefurther examples, an attachable suction head or port may be coupled tothe severed end of the tubing 1402 after customization. In still furtherexamples, a puncture tool may be applied to the severed end of thetubing 1402 to form a plurality of side openings in the low profiletubing 1402 facing the treatment site, rather than solely rely upon theexposed lumen end of the low profile tubing 1402 for suction.

In some embodiments, the dressing comprises transparent material in atleast a partial section of the surface to allow inspection of the wound,wound contact material or peri-wound skin under the dressing. In someembodiments, the dressing further comprises flaps which may bereversibly adhered to transparent sections of the dressing. These flapsmay be substantially opaque or appropriately colored to cover and hidethe underlying dressing and general wound region. In some embodiments,the dressing comprises a singular flap. In some embodiments, thedressing comprises a plurality of said flaps.

FIG. 4 illustrates an example of a reduced pressure treatment system 400configured to permit selective viewing under a substantially opaquedressing 401. Dressing 401 may be attached to port 402 as previouslydescribed. Dressing 401 further comprises opaque flaps 403 which coversubstantially transparent regions 404 of dressing 401. Transparentregions may comprise polyurethane, silicone, transparent hydrocolloid,hydrogel, copolyester, polyethylene or any other substantiallytransparent material known in the art. Flaps 403 may further bereleasably adhered to transparent regions 404 by a weak adhesion such asstatic adhesion, weak chemical adhesive or any other weak adhesivemethod known in the art. The dressing may also be configured toreleasably adhere or attach to other portions of the sealant to maintainthe flaps in a closed position during viewing or access. Flaps 403 maycomprise hinge elements 405 to permit reversible adhesion to transparentregions 404 of dressing 401. Flaps 403 may also rest flush in a closedposition 406 which occludes visibility of transparent regions 404. Thedepicted embodiment comprises a four-fold flap configuration orientedaround port 402. In some variations, the flaps are configured to overlapbeyond the borders of the transparent regions to facilitate grasping andlifting of the flaps. In these variations, one or more overlappingregions may be provided without any adhesive or weak adhesionproperties.

FIG. 5 illustrates an alternate configuration of a bi-fold flaptreatment system 500. Dressing 501 may be configured with a port 502 asdescribed previously. Dressing 501 comprises opaque flaps 503 whichcover transparent regions 504 of dressing 401 in the manner described inFIG. 4. Flaps 503 may further comprise cutout features 507 toaccommodate geometry of port 502.

In some further embodiments, a dressing application system or reducedpressure treatment system further comprises one or more applicatorelements located above and/or below the dressing to support andfacilitate the application of the dressing to the desired body site, andmay also improve air-tight sealing of the dressing to the body surface.One potential function of these applicator elements is to easeapplication by providing sufficient rigidity to the dressing such thatit does not easily fold and buckle and consequently stick to itself whenthe adhesive layer is exposed. Secondly, when the dressing is applied,the dressing system may be held and grasped while avoiding contact withthe adhesive elements of the dressing to permit simpler application tothe desired surface. Third, the dressing system is customizable toaccommodate specific anatomical contours. When the dressing system isshaped, for example, by cutting the dressing system, the functionalelements that permit simple application of the dressing to a wound siteare preserved.

In some embodiments of the dressing system, the dressing system includesat least one support layer that maintains sufficient system rigidityonce an adhesive surface is exposed while a secondary element to thedressing system comprises a layer or series of layers that shield theuser from inadvertent contact with the adhesive components of thedressing prior and/or during application. These elements serve toalleviate the existing problems with dressing application that lead topoor dressing seating characteristics such as the presence of wrinklesdue to buckling and resultant channels in the dressing. The embodimentsdescribed herein are directed toward more effective adhesion of adressing to a desired body site.

In one exemplary configuration, the support layer is releasably attachedor adhered to the facestock of the dressing and can be detached from thedressing once the user deems appropriate such as after the dressing hasbeen secured to the body site. This support layer may comprise a stiffcarrier element that may be configured to include break lines or foldsthat facilitate easier lifting up of an edge of the material for simpleremoval. The positioning and design of the break line is also such thatcutting of the dressing to a smaller size allows the break lines toremain accessible. This carrier element may be clear or translucent tofacilitate visualization of underlying components of the dressing systemand the body site to which it is attached provided the dressing issufficiently clear or translucent. A polyurethane or other similarlyconceived material with sufficient rigidity may be used as a carrierelement. In another exemplary configuration, a paper stock may be usedwith a weak adhesive to provide support to the dressing. The break linemay be introduced by kiss-cutting an already adhered carrier film on topof the dressing or cut prior to application to the dressing. The carriermay also comprise at least one opening, or window, that allows directaccess to the dressing, and may be configured such that a conduit (e.g.a port and/or tubing) can pass through it to permit communication ofreduced pressure to the volume below the dressing. The location of thebreak line in the carrier film may also configured to allow for ease ofremoval when a reduced pressure conduit such as a port and attachedtubing are present on the dressing.

In another embodiment, separate or in combination to the support layerare elements attached to the adhesive element of the dressing arerelease handles that mitigate user interaction with the adhesive duringapplication to prevent inadvertent adherence of the dressing to theindividual applying the dressing. These handles can take the form ofcoated polymeric sheets folded back on themselves to allow simpleremoval after initial adherence of the dressing to the body site. Therelease handles may be transparent or translucent to permitvisualization through a clear or translucent dressing and carrier oropaque. The handles may be formed from a laminated sheet such as asilicone treated paper, fluorosilicone, or fluoropolymer treated filmfor example. The folds of the handles may be spaced sufficiently closeto the center of the dressing such that the fold that is not adhered tothe dressing remains present even when the dressing is cut to a smallersize for customization. At least one of these release handles isoriented along the dressing surface, typically along the perimeter ofthe dressing. For example, two sets of opposing release handles may bepositioned in such a manner to cover the edges of a rectangulardressing. Another element may also be present to cover and protect theadhesive between the release handles prior to dressing application. Thislayer similar to the release handles may be transparent or translucentto permit visualization through a clear or translucent dressing andcarrier or opaque. The release liner may be formed from a laminatedsheet such as a silicone treated paper, fluorosilicone, or fluoropolymertreated film for example. With the upper support layer and lower releasehandles elements in place, the stiffening and adhesive shielding aspectsof the two elements are preserved even with dressing shapecustomization.

FIG. 15 illustrates one example of a carrier element 1500 that may beused with a dressing or dressing. The carrier element 1500 may comprisea material and/or construction that has greater rigidity to helpmaintain the shape of the dressing during application or preparation.The carrier element 1500 may be releasably attached to adhesive layer orhydrocolloid layer located on the lower surface 107 of the dressing 101,but may also be configured for use on the upper surface of the dressing101 by providing a central opening to accommodate the port 102. FIG. 23,for example, illustrates a carrier element 2300 with a central windowregion 2301 that allows exposure of the underlying dressing 2302 and toaccommodate a port member or tubing. Curved break lines 2302 permitremoval of the carrier subelements 2303 from dressing 2302. Atranslucent or transparent dressing may be provided to visualization ofthe underlying treatment site.

Referring back to FIG. 15, the carrier element 1500 comprises at leasttwo subelements 1501 with a non-linear break line 1502 between them tofacilitate lifting or separation of the subelements 1501 from thedressing 101. Although the break line 1502 depicted in FIG. 15 comprisesa sinusoidal configuration, any of a variety of linear or non-linearconfigurations may be provided. In other variations, more than twocarrier subelements may be provided, with two or more break lines thatmay be separate or branching. In still other examples, folded oroverlapping tabs may be provided.

FIG. 16 illustrates an alternate configuration for a carrier element1600 comprising two subelements 1601 with a break line 1602 having atleast one segment 1603 that has a non-orthogonal orientation withrespect to the closest edge 1604 of the carrier element 1600. The breakline 1602 also comprises a linear segment 1603, which may or may not bethe same as the non-orthogonal segment in every embodiment. When thecarrier subelement 1601 is separated from dressing at the narrowerregion 1605, the peel force required for separation may be reduced as aresult of the reduced contact width or transverse dimension to thedirection of separation.

FIG. 17 illustrates another configuration for a carrier element 1700,comprising an interior or central window region 1701 that allowsexposure of the underlying dressing elements. One or more break lines1702 may be provided between an outer edge 1703 and an inner edge 1704of the carrier element 1700. Where multiple break lines are provided,the break lines 1701 may be located at symmetrical locations to separatethe carrier element 1700 into similarly sized and shaped subelements1705, but in other variations, the break lines may be asymmetricallylocated.

FIGS. 18A to 18D illustrate a dressing system 1800 with a window 1801 inthe carrier element 1802 to expose the underlying dressing or dressing1803, and to accommodate a port (not shown) attached to the dressing1803. The dressing system 1800 further comprises an interior releaseliner 1804, and two release handles 1805. The carrier element 1802provides an increased stiffness and support to the dressing 1803 duringapplication to a treatment site, while the window 1801 permitsvisualization of the treatment site to facilitate positioning of thedressing 1803. The interior release liner 1803 protects the adhesivelayer of the dressing 1803 against inadvertent adhesion until the userdetaches the liner 1803 prior to application. To expose the centralportion of the dressing 1803, the free flaps 1808 of the interiorrelease liner 1803 may be grasped to separate the liner 1803. The tworelease handles 1805 permit handling or grasping of the dressing 1803without adhering to the adhesive layer on the lower surface of thedressing 1803. Once the exposed adhesive layer from the removal of theinterior release liner 1803 is adhered to the desired treatment site,the free flaps 1806 of the release handles 1805 may be grasped andpulled to separate the adhered flaps 1807 of the release handles 1805from the dressing 1803 to expose the remaining adhesive layer and permitcomplete adhesion of the dressing 1803 to the treatment site. Once thesecured, the carrier element may be separated from the dressing 1803.

FIGS. 19A and 19B depicts the dressing system 1800 in FIGS. 18A to 18Dafter multiple cuts 1900-1904 were made to customize the system 1800 toa particular shape while maintaining its functionality. FIG. 19B is aperspective view of the underside of the dressing system 1800,illustrating that the release liner 1804 and release handles 1805maintain their respective forms and functionality even after thedressing system 1800 and the dressing 1803 has been cut.

For simplification purposes, FIGS. 18A to 18D depicted the dressing 1803with the attached port member. FIG. 20, depicts dressing system 1800 inintact form, with the carrier element 1802 with carrier window 1801surrounding the port assembly 1810 and tubing 1811 of the dressing 1803.Note that the break line 1812 in the carrier element 1802 is located insuch a manner as to allow simple removal of the carrier element 1802with the reduced pressure conduit present, e.g. minimizing interferencefrom the port assembly 1810 and tubing 1811.

In further configurations of the device, reinforcements such as embeddedrings or ridges may be incorporated into the dressing system. Thesestructures or elements may streamline the application of reducedpressure dressings by mitigating buckling of the dressing andself-adherence of the dressing, and may also improve the ability of thedressing to form and maintain an airtight seal once it has been appliedby reducing the wrinkling that may occur otherwise during application.In addition to dressing adhesive thickness, these elements may permitlonger term delivery of reduced pressure to an area of tissue damage byproviding a more robust seal with less ability to leak. Furthermore, theuse of continuously running powered pumps to create reduced pressure maybe obviated because the seal may be more robust than traditional RPWTdressings and may exhibit reduced or substantially no leakage. This typeof treatment is less feasible using traditional reduced pressure sealantdressings.

FIGS. 21A and 21B depict one embodiment of a dressing system 2100,comprising a thick adhesive layer 2101 (e.g. at least about 500 micronsor greater) and circumferential reinforcement structures 2102surrounding the port member 2105, which may reduce buckling/wrinkling ofthe dressing system 2100. Although each of the reinforcement structures2102 in FIGS. 21A comprises contiguous, closed configuration structures2101, in other variations the structures may be segments and/or comprisea generally open configuration, e.g. C-shaped. In addition to the thickadhesive layer 2101, the dressing system 2100 further comprises aperimeter region 2103 with increased adhesive properties than theinterior region 2104. In some situations, a more increased adhesionaround the perimeter 2103 of the dressing 2100 may further helps tomaintain dressing adhesion. In some variations, the difference in peelforce between the perimeter 2103 and the interior region 2104 may beabout 1 N to about 10 N for specimens about 25 mm in width, sometimesabout 2 N to about 8 N, and other times about 1 N to about 4 N. Thedifference in probe tack force may be about 0.5 N to about 3 N with aninitial loading of about 100 kPa, sometimes about 0.75 N to about 2 N,or other times about 0.5 N to about 1.5 N. In some further variations,the interior region 2104 may completely lack any adhesive. Othervariations of the adhesive properties of the dressing were previouslydescribed herein.

FIGS. 22A and 22B depict another example of a dressing system 2200 witha thick adhesive layer 2201 and radial reinforcements 2202 surrounding aport member 2206 to reduce buckling/wrinkling of the dressing. A thinneradhesive skirt 2203 around the perimeter of the dressing system 2200 isalso provided. The thinner adhesive skirt 2203 may be tapered inthickness or may have a uniform thickness. The thinner perimeter alsomitigates lifting of the dressing edge from the body surface. Thedressing system 2200 may be applied by removing a central liner 2204 toexpose the thick central adhesive layer 2201 first for application tothe body surface, then a second perimeter liner 2205 is removed toexpose and to adhere the adhesive skirt/border 2203.

FIGS. 24 depicts a dressing or dressing 2400 comprising relativelythicker and thinner regions 2402 and 2404 that may permit greaterconformability of the dressing 2400 on the body surface. The thickerregions may be comprised of a thicker hydrocolloid adhesive materialwhile the thinner areas may be comprised of thinner hydrocolloid orelastic polyurethane or other similar material. In some examples, thethicker hydrocolloid adhesive regions may have a thickness in the rangeof about 0.2 mm to about 2mm, sometimes about 0.3 mm to about 1.5 mm,and other times about 0.5 mm to about 1 mm. In some further examples,the thinner hydrocolloid adhesive regions may be in the range of about0.15 mm to about 1.5 mm, sometimes about 0.2 mm to about 1.2 mm, andother times about 0.5 mm to about 0.8 mm. The thickness ratio betweenthick regions and the thin regions may be in the range of the 1.2:1 toabout 3:1 or more, sometimes about 1.5:1 to about 2:1 and other timesabout 1.3:1 to about 1:6:1. In this particular embodiment, the regions2402 and 2404 are arranged or organized in an orthogonal grid fashionwhere the thick regions 2402 comprise square shapes. In other examples,the thick regions may comprise other shapes, e.g. circles, stars. etc.,while in still other examples, the relationship between the thick andthin regions may be reversed, e.g. a waffle configuration wherein thethick regions comprise the grid lines and the thin regions comprise thesquare shapes.

FIG. 25 depicts another example of a dressing 2500 comprising thick andthin regions 2502 and 2504 with the thin regions 2504 completelysurrounding each thick region 2502 such that greater extension andstretch of the dressing 2500 may be permitted. The thicker regions 2502may comprise linear members having a generally radial orientationrelative to the center of the dressing 2500. As depicted in FIG. 25, thethick regions 2502 may have variable lengths and widths. The thickregions 2502 may comprise thick hydrocolloid adhesive material while thethinner regions 2504 may comprise of thinner hydrocolloid or elasticpolyurethane or other similar material.

To further augment the leak resistance characteristics of the reducedpressure treatment system, a spray-on, paint-on or otherwise initiallyfluid-based dressing may be utilized. In some embodiments a flexibleand/or adjustable dam, stencil, mask or containment apparatus that maybe placed around the treatment site. The dam may be configured inmultiple sizes and/or shapes for specific anatomic locations and incertain configurations has a soft, bottom edge that can conform tomultiple body location sites to form a near fluid resistant seal. Incertain embodiments, the dam is further equipped with a mechanism tohold a RPWT conduit. In some embodiments, the dam may be furtherequipped with a holder for a RPWT dressing (foam or gauze, or other).Upon positioning the dam around the wound, the dressing, which maycomprise any of variety of fast curing polymers or other similarlybehaving materials, is sprayed or otherwise applied over the treatmentsite to create an airtight seal and enclosure around the site, thedressing, and portion of the conduit in fluid communication with thesite. In certain embodiments, the applied substance may be a fastsetting silicone or latex. In some embodiments, a RPWT conduit may beapplied after forming the airtight enclosure with the applied dressing.In such an embodiment, the user may create an opening in the applieddressing in order to attach the conduit. The opening may be pre-formedduring spraying or formed after spraying. In some embodiments, theconduit is attached to the airtight enclosure with an adhesive. In someembodiments, the applied dressing may shrink about 1% to about 10% ormore in size as it cures to draw the wound edges inward to promotefaster wound closure/wound healing. In other examples, a liquid dressingmay be applied by brush, roller, or simply spread or squeezed over thetreatment site.

FIGS. 26A to 26C illustrate one example of a procedure and system thatmay be used to apply a spray-on or otherwise applied dressing over awound with a drape or containment element to control the distribution ofthe dressing. First, a reduced pressure conduit 2600 is placed over awound contact material 2601 and then a drape 2602 is placed around wound2603. A spray sealant material 2604 over the wound 2603 and contactmaterial 2601 with some coverage of the drape 2602. The drape 2602 isthen removed and the sealant material 2604 is permitted to cure/set toform an air-tight barrier.

FIG. 27 illustrate an optional structure and procedure that may be usedwith that depicted in FIGS. 26A to 26C, wherein a mesh or netting 2700is applied after applying the contact material 2601 to the treatmentsite but either before (as depicted in FIG. 27) or after the spraying ofthe dressing. In some examples, applying the netting 2700 first may helpto hold and/or capture the applied sealant, for example, by surfaceforces. The port 2600 may be placed on prior or after application of thedressing material to create a conduit between the reduced pressuresource and the wound.

FIG. 28 illustrates another system 2800 configured to apply a spray-onsealant material to treatment site 2801, comprising a cuff 2802 with aRPWT conduit holder 2803. In use, after preparing the treatment site2801, a wound contact material 2804 is applied to the treatment site2801, then the cuff 2802 is placed around the treatment site 2801 andthe port 2805 is positioned over the contact material 2804 and held inplace by the port/tubing holder 2803. The sealant material is thensprayed into the opening or cavity 2806 of the cuff 2802 to seal thetreatment site 2801 and the port 2805 to the treatment site 2801.Although the conduit holder 2803 is depicted as being located on thesuperior surface of the cuff 2802, in other variations, the conduitholder may be located on a side wall 2807 of the cuff 2802. Also, thecuff need not have the circular configuration as depicted in FIG. 28,and may have any of a variety of shapes, or may even be plasticallydeformable or malleable to provide a customized masking shape.

It is to be understood that this invention is not limited to particularexemplary embodiments described, as such may, of course, vary. It isalso to be understood that the terminology used herein is for thepurpose of describing particular embodiments only, and is not intendedto be limiting, since the scope of the present invention will be limitedonly by the appended claims.

Where a range of values is provided, it is understood that eachintervening value, to the tenth of the unit of the lower limit unlessthe context clearly dictates otherwise, between the upper and lowerlimits of that range is also specifically disclosed. Each smaller rangebetween any stated value or intervening value in a stated range and anyother stated or intervening value in that stated range is encompassedwithin the invention. The upper and lower limits of these smaller rangesmay independently be included or excluded in the range, and each rangewhere either, neither or both limits are included in the smaller rangesis also encompassed within the invention, subject to any specificallyexcluded limit in the stated range. Where the stated range includes oneor both of the limits, ranges excluding either or both of those includedlimits are also included in the invention.

Unless defined otherwise, all technical and scientific terms used hereinhave the same meaning as commonly understood by one of ordinary skill inthe art to which this invention belongs. Although any methods andmaterials similar or equivalent to those described herein can be used inthe practice or testing of the present invention, some potential andpreferred methods and materials are now described. All publicationsmentioned herein are incorporated herein by reference to disclose anddescribe the methods and/or materials in connection with which thepublications are cited. It is understood that the present disclosuresupersedes any disclosure of an incorporated publication to the extentthere is a contradiction.

It must be noted that as used herein and in the appended claims, thesingular forms “a”, “an”, and “the” include plural referents unless thecontext clearly dictates otherwise. Thus, for example, reference to “ablade” includes a plurality of such blades and reference to “the energysource” includes reference to one or more sources of energy andequivalents thereof known to those skilled in the art, and so forth.

The publications discussed herein are provided solely for theirdisclosure. Nothing herein is to be construed as an admission that thepresent invention is not entitled to antedate such publication by virtueof prior invention. Further, the dates of publication provided, if any,may be different from the actual publication dates which may need to beindependently confirmed.

The preceding merely illustrates the principles of the invention. Itwill be appreciated that those skilled in the art will be able to devisevarious arrangements which, although not explicitly described or shownherein, embody the principles of the invention and are included withinits spirit and scope. Furthermore, all examples and conditional languagerecited herein are principally intended to aid the reader inunderstanding the principles of the invention and the conceptscontributed by the inventors to furthering the art, and are to beconstrued as being without limitation to such specifically recitedexamples and conditions. Moreover, all statements herein recitingprinciples, aspects, and embodiments of the invention as well asspecific examples thereof, are intended to encompass both structural andfunctional equivalents thereof. Additionally, it is intended that suchequivalents include both currently known equivalents and equivalentsdeveloped in the future, i.e., any elements developed that perform thesame function, regardless of structure. The scope of the presentinvention, therefore, is not intended to be limited to the exemplaryembodiments shown and described herein. Rather, the scope and spirit ofpresent invention is embodied by the appended claims. For all theembodiments described herein, the steps of the method need not beperformed sequentially.

1. A device for providing reduced pressure treatment of a location on apatient, comprising: a cover structure comprising an upper surface, alower surface and a first opening extending through the cover structurefrom the upper surface to the lower surface, wherein the opening iscapable of communicating with the location when the device engages withthe patient; and a port assembly configured to fluidly couple to anegative pressure source, wherein the port assembly comprises: a firstwall coupled to the upper surface of the cover structure and having asecond opening in fluid communication with the first opening; acompliant second wall; and a volume between the interior and second wallin fluid communication with the negative pressure source, the volumecapable of being in fluid communication with the location when thedevice engages with the patient, wherein the compliant second wall isdeformable upon exposure of the volume to a negative pressure from thenegative pressure source.
 2. The device of claim 1, wherein the secondwall provides an indication of the negative pressure under the coverstructure at the location.
 3. The device of claim 2, wherein the secondwall provides an indication that the negative pressure under the coverstructure at the location is lost.
 4. The device of claim 2, wherein theindication is visible or tactile or both.
 5. The device of claim 1,wherein the exposure of the volume to negative pressure reduces thevolume and deforms the second wall to approach the first wall.
 6. Thedevice of claim 5, wherein an upper surface of the first wall comprisesa visually distinctive region.
 7. The device of claim 6, wherein thesecond wall is translucent and the visually distinctive region isobscured by the second wall when the second wall is a distance from thefirst wall.
 8. The device of claim 7, wherein the visually distinctiveregion is visible through the translucent second wall when the secondwall is less than the distance from the first wall.
 9. The device ofclaim 6, wherein the visually distinctive region comprises a color,pigment, symbol, pattern, or text.
 10. The device of claim 2, whereinthe second wall is a first color and the first wall is a second colorsuch that contact between the second wall and the first wall provides avisible indication of a presence of the negative pressure under thecover structure at the location.
 11. The device of claim 1, wherein thelocation on the patient is at least in part external to a skin region ofthe patient.
 12. The device of claim 1, wherein the location on thepatient is at least in part internal to a skin region of the patient.13. The device of claim 1, wherein the compliant second wall deformsfrom at least a first profile to at least a second profile upon exposureof the volume to the negative pressure.
 14. The device of claim 13,wherein relative position of the compliant second wall between the firstprofile and the second profile is indicative of an amount of negativepressure delivered to the location.
 15. The device of claim 1, whereinthe first wall is an interior wall and the second wall is an exteriorwall.
 16. A device for providing reduced pressure treatment of alocation on a patient, comprising: a cover structure comprising an uppersurface, a lower surface and an opening extending through the coverstructure from the upper surface to the lower surface, wherein theopening is capable of communicating with the location when the deviceengages with the patient; and a pressure indicator fluidly coupled tothe opening in the cover structure, wherein the pressure indicator isconfigured to fluidly communicate with a negative pressure source andcomprises, during use, at least a first profile prior to exposure of thelocation to the negative pressure and at least a second profile uponexposure of the location to the negative pressure.
 17. The device ofclaim 16, wherein the first profile of the pressure indicator is greaterthan the second profile of the pressure indicator.
 18. The device ofclaim 16, wherein the first profile of the pressure indicator is convexand the second profile of the pressure indicator is concave.
 19. Thedevice of claim 16, wherein the pressure indicator comprises anelastomeric membrane coupled to at least a portion of the coverstructure.
 20. The device of claim 16, further comprising a portassembly fluidly coupled to the cover structure and the pressureindicator, wherein the port assembly is configured to deliver negativepressure from the negative pressure source to the location.
 21. Thedevice of claim 20, wherein the pressure indicator comprises anelastomeric membrane surrounding at least a portion of the portassembly.
 22. The device of claim 20, further comprising tubing coupledto the port assembly at a first end and coupled to the negative pressuresource at an opposite end, wherein the tubing comprises a sidewallhaving at least one sidewall opening.
 23. The device of claim 22,wherein the pressure indicator comprises an elastomeric membranesurrounding the at least one sidewall opening of the tubing.
 24. Thedevice of claim 16, wherein the pressure indicator comprises an internalvolume configured to be reduced upon exposure of the location to thenegative pressure and to move the pressure indicator from the firstprofile to the second profile.
 25. The device of claim 16, whereinrelative position of the pressure indicator between the first profileand the second profile is indicative of an amount of negative pressuredelivered to the location.
 26. The device of claim 16, wherein thelocation on the patient is at least in part external to a skin region ofthe patient.
 27. The device of claim 16, wherein the location on thepatient is at least in part internal to a skin region of the patient.